Electrical switch



H. D. JAMES.

ELECTRICAL SWITCH. APPLICATION FILED SEPT. I, 1917.

WITNESSES:

Patented Nov. 15,1921.

I INVENTOR I fl b/ya James UNITED STATES PATENT OFFICE.

HENRY D. JAMES, OF EDGEWOOD PARK, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION 013 PENNSYL- VANIA.

ELECTRICAL SWITCH.

Specification of Letters latcnt.

Patented Nov. 15, 1921.

T 0 all 20 hom it may concern:

Be it known that I, HENRY D. JAITES, a citizen of the United States, and a resident of Edgewood Park, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Electrical Switches, of which the following is a specification.

My invention relates to electrical switches and particularly to switches that are provided with underload trips.

One object of my invention is to provide an underload trip for a switch that shall be constructed in a manner to prevent the closing of the circuit of the 'electromagnet for the underload trip unless the magnetic circuit thereof is closed.

In many switches now in service and particularly in automatic starting switches for motors that are provided with underload trips, it is possible to have the circuit closed through the electromagnet of the underload trip when the armature associated therewith is in an inoperative position. If the armature is in an inoperative position, it is apparent that the reluctance of the magnetic circuit of the underload electromagnet must necessarily be substantially increased, inasmuch as the magnetic circuit is open. An increase in the reluctance will increase the heat produced by the electromagnet of the trip and, in many cases, damage the coil or destroy the effective operation of the trip. The coil of an underload trip must necessarily be delicate in construction and somewhat sensitive to perform the functions required thereof, and, necessarily, an increased current and an abnormal heating effect tend to destroy the effectiveness of the underload trip.

However, in a switch constructed in accordance with my invention, an auxiliary switch, which is inserted in series with the coil of the underload trip, is controlled by the armature of the trip magnet in a man ner to prevent the energizing of the trip magnet when the armature is in an inoperative position and the magnetic circuit thereof is open. Thus, the coil of the tripmagnet is protected against an increased current and an increased heating effect by reason of the opening of the magnetic circuit thereof.

The single figure of the accompanying drawing is a diagrammatic view of an underload trip switch that is constructed in accordance with my invention.

Referring to the drawing, an underload trip 1 embodies a coil 2, which is mounted upon a magnetic structure 3, and an armature 4: which is pivotally supported upon the magnetic structure 3 in any convenient manner. The armature 4: is provided with an arm 5 having a contact terminal 6 mounted thereon which cooperates with a stationary contact terminal '7. The contact terminals 6 and 7 serve as an auxiliary switch for preventing the closing of the electric circuit of the coil 2 when the armature 4. is in an inoperative position.

An arm 8,- which is pivotally mounted near one end thereof and is provided with a pin 9 near the opposite end thereof, serves for closing a main switch 10 and for forcing the armature a into contact with the magnetic structure 3. If the coil 2 of the underload trip is energized, the arm 8, when moved manually or in any convenient manner, toward the left, as shown on the drawing, is held in its extreme position by means of a latch 11. The latch 11 projects from the armature 4 and engages the pin 9. In case the coil 2 is deenergized, a suitable spring 12 is provided for returning the. arm 8 to an inoperative position and for opening the switch 10.

From the above description, it will be noted that the armature 4 serves to prevent the energizing of the coil 2 unless the magnetic circuit thereof is complete and the armature at is in an operative position.

Modifications in the structure and location and arrangement of parts may be made within the spirit and scope of my invention and such modifications are intended to be covered by the appended claims.

I claim as my invention:

1. The combination with a magnetizable member and a coil for energizing said member, of an armature member mounted upon said magnetizable member and adapted to occupy a position in which it completes the magnetic circuit of said magnetizable member and effects the completion of the circuit of said coil, and means for actuating said armature member into said position and operatively engaging said armature member while it occupies said position.

2. The combination with a movable member biased to an inoperative position, of

means for retaining said member in an operatlve position, sald means compr slng an electromagnet having a coil and an arma ture member and means associated with said armature member for simultaneously effecting the energization of said coil and the operative engagement of said movable member.

3. In a switch, the combination with an underload trip comprising a coil, and a core and an armature associated with the coil, of a pair of main contact terminals, an arm for simultaneously closing the main contact terminals and for moving said armature into engagement with the core, and means controlled by the armature for preventing the energizing of the coil until the armature is man operative position. 7

l. In a switch, the combination with an underload trip comprising an electromagnet and an armature associated therewith, of an auxiliary switch controlled by the armature for opening the circuit of the electromagnet when the armature is in an inoperative position, an arm for moving the armature into engagement with the electromagnet, and a latch on said armature for holding said arm in the operated position.

5. In a switch, the combination with an underload trip comprising an electromagnet and an armature associatedtherewith, of an auxiliary switch operated by the armature for preventing the closing of the electric circuit of the electromagnet when the armature is in an inoperative position, a main switch, an arm for closing the main switch andfor moving the armatureto an operative position, and means provided on the armature for holding said arm to maintain the main switch closed when the electromagnet is energized. V I

6. The combination with an electromagnet comprising a magnetizable member, an energizing coil and an armature member, of a latch member operatively connected to said armature member, a switch member operatively connected to said armature member for controlling the circuitof said coil, and a member for actuating said armature member into operative position and for operatively engaging said latch member.

7 The combination with an electromagnet comprising a magnetizable member, an energizing coil and an armatureimember, of a latch member operatively connected to said armature member, a switch member operatively connected to said armature member for controlling the circuit of said coil, and means for actuating said armature member into operative position to render said switch member andsaid latch simultaneously. v

In testimony whereof, I have hereunto subszcribed my name this 21st dayof August 191 member efiective HENRY D. JAMES. 

